Method of making rice straw pulp and apparatus therefor



P. SWAN METHOD OF MAKING RICE STRAW PULP AND APPARATUS THEREFOR Filed June 1, 195

[NI/B117 3 ing the material.

Patented May 17, 19 32" i s uNi EnfsT T-Es PATENT ors ce v ram SWAN, onlronrnann, onneon umnon on marine nice STBAW PULP AND Arruwrns 'rnmmron" Application filed June 1, 1931. Serial no; 541mg.

This invention relates to a soda process of the neck 12. Cylinders 1'1 and 18 mounted making rice straw pulp using certain formuto rotate in spaced relation and in opposite lated treatments and providing improved apdirections in the mouth of the hopper 8 paratus for conveying, shredding and beatare keyed toasuitableshafts 20 and 21 re- 1 spectively, having hearings in the walls- ,of 55 Among theobjects of my invention is'the the hopper and made to rotate at difierentireduction pf the time required to produce the "ated speeds and in opposite directions by a pulp and with the minimum amount of appair of gears 22 and 23 and a driver pulley paratus. The time-saving and simplifica- 25. Each of the} cylinders is armed with a 10 tion of the process is a/direct result of much series of radial cutting teeth 26 which are reduced period-of cooking, so that the straw arranged to overlap and cut upand shred the used in the cookers is merely cured but in stock passlng between thejrolls into the hopno way reduced to pulp. v per, where water is added.

The apparatus and machines required in The rod mill 10 has a.horizontal, cylin- '15 my process are shown in the following drawdrical drum 27 mounted to rotate in roller ings, in which cradles 28. and driven by an annular rack Figure 1 is a side elevationalview of the and pinlon 30 of usual construction. The various machines employed "in the process intake end of the drum 27 has a head 31proof producing pulp according to my invenvided with the concentric opening 13, above '20 tion shown diagrammatically with certain mentioned while the discharge end 32 has a m partsshown broken and in section. relatively larger concentric opening 33pro- Fig. 2 is a fragmentary side elevational vided with anadjustable gate 34. The inview in vertical section and on an enlarged terior of the drum, see 5, is divided into scale, of the feed hopper to the rod mill three equal compartments 35, 36 and 37 by 25 shown in Fig. 1. I similar partitions 38 normal to the axis of Fig. 3 is a detached plan view of fibre the drum and.having concentric openings 40 shredding and cutting elements provided in therein of a size between that of the 0 enthe hopper shownin Fig. 2. 1 ings 13 and 33. 'The inner walls of shell of Fig. 4 is a plan view of one of the washthe drum'27 are linedvvith wood and a luing units shown in Fig. 1 certain intake and rality of rods 41 of suitable length and of overflow pipes between units being shown different sizes are placed loosely in the sevin broken condition. eral compartments and disposed parallel to Fig; 5 is aside elevational view in vertithe axis of the drum, so that the rods will. cal section of the cylinder of the; rod milh be free to roll and tumble in the compart- 5 shown in Fig. 1. r .ments upon rotation, of the drum.

Referring to the above views, chutes 1 are Washing units 42 for washing the pulp provided for loading rotary steam cookers are arranged in series behind the rod mill 2 of usual constructionmounted to "rotate so that pulp discharged from the opening on' trunnion bearings 3. A belt '5 below the .33. will all onto an. apron 43' leading into cookers serves to convey away the cured. the .first unit, where a supply of water, not 90.

,stock emptied from the cookers. This belt shown, and certain chemicals later to be de- ,empties onto another cross, belt 6 which scribed, are added to the pulp, which will empties into a bucket elevator 7 of usual flow in a' manner to be presently described,

design, which in turn delivers tlie stock into, from one unit to the next through connecta hopper 8 for supplying stock to 'a rod mill ing pipes 45 and finally out through dis- 10. The hopper is supported on a base 11, charge pipes 46 for delivery to the paper maand has a discharge neck 12'extending into chines or other'parts of the mill as desired. an opening 13 in one end of the rod mill. The washing units are of similar construc- A screw propelling shaft 14 mounted in beartion and working in unison, so that only one 9 ings 15 and driven by a pulley 16 extends into need be describe Each unit', see Figs. 1 and 7/ 4:, consists of a box 47 for holding the-liquid, provided with an intake compartment 48, opening near the bottom at 50 into a middle settling chamber 51 and a spillway compartment 52. A cylinder 53 extending long1- tudinally of the chamber l in its "HPPGI" portion is,mounted to rotate in bearings in the ends of the boxand is driven by a pulley 55. The liquid is allowed to fill the box to approximately 5: below the top of the cylinder, the exposed surface of the cylinder rotating toward the spillway 52 where a wipinggelement 56 flexibly contacting the cylinder over the length of the box drains intoithe spillway, so that pulppassing from one box to the next will be washed from im purities in-the chambers 51 and floating to r the top of the liquid will be carried over the successive cylinders.

To prepare pulp from rice strawin the mill described, place causti'cized liquor, later to be described, in-th'e cooker 2, adding 1 pounds of salt cake for each cubic foot of liquor and fill the cooker with straw in the proportion of 169 cubic feet of liquor to the ton of straw. The contents are allowed to cook forAO minutes. he straw thn is let fall upon the belt 5 and taken in unbroken conditionto the hopper 8 by way of -the conveyor 7. The cooked straw is engaged by the cutting t eth 26 on the shredding cylinders 17 and and is shredded and cut and cari'ied down into the neck of the hopper where the,worm 14 forces it into the compartment of the rod mill where 5% volume of soda .ash is admixed, in\order to harden the stock,

while the drum 27 is in rotation. Theaction r of the tumbling rodq-reduces the straw to pulp, the pulp passing from one 'compart ment to the next through the openings 40' v and isfinally spilled onto the apron 43 where a 2 solution of bicarbonate of soda is added- The pulp entering the compartment and through the o ening into the chamber 51 where it W111 be washedrand rise to the liquid level and be carried overthe revolving cylinder53 apd be scraped off by the scraper 5fr and pass out through the 50 spillway 52 into'the next washing box and finally through the dischar e pipes 46 for further refinement or direct yto the paper 111 chines.

he,white liquor above referred to should. have a strength reading 5 Bauui and should be CllllStlClZQd to approximately 86% with the addition "of 5% sulphur while causticizmg. v A convenient test of the causticization'is 39 to take 50 parts of the cooking liquor to 250,

parts of water adding bariumchloride and j slackening and letting 'stand.- Then using 25 parts with methyl oran as indicator and using iodine for Bareet reading. Having described my invention, claim:

ing the shredded stock into a rod mill,-a rod mill formeducing the stock to'pulp, and-wash.

48 of the first washer will pass downwardly 1. A method of making rice straw pulp consisting in cooking rice straw in a cooker coiitaining causticized liquor for approximately 40 minutes, in order to impregnate the I straw with the liquor, but without changing the structure of the straw, in withdrawing thestraw from the cooker and conveying the straw to a hopper and'there passing. it be- I tween armed cylinders for cutting and shred- 1% pounds of salt cake per cubic foot of the mixed liquors, using 1 /4 pounds of lime per cubic foot of liquor for causticizing to approximately 86% and adding 5% of sulphur; in conveying the unbroken straw thus im-1' pregnated with'the liquor over bucket con veying elevators to fibre-shredding and cutting apparatus, in hydrating the shredded stock, adding 5% of soda ash and passing the 9 stock throughai'od mill where it is reduced to pulp and then finally washed in suitable washing boxes and delivered to screens.

3. In pulp making apparatus the combina: tion of cookers for impregnating the raw material with causti'cized liquor, conveying and elevating elements, for carryin and regulating the travel of the cooked stoc ,fibre-shredding mechanisms, propelling means for feeding mechanism for washing the pulp. 4. A straw-shredding and cuttingmachine consisting of a hopper, spaced, parallelcylinders extendin throughthe mouth ofthe hopper, a plura ity 0t cutting'arms on the cylinders. arrange to overlap inthespace between the cylinders, means of'r'otating the cylinders in o positedirections and at. different. rates 0. speed, and means pf. deliver ing the stockshredded and cut by the cylin-' r ders from theneck of the hopper. a

i I PETER SWAN.- v 

